There are two main groups of power amplifier in an NVA hi-fi system:
- Stereo: Two channel amps - inc. S80, S150 & S300.
- Mono-block: Single channel amps (in matching pairs) - inc. M160, M300 & M600.
P50 PRE-AMP PLUS SINGLE STEREO POWER AMP
Stereo models are the most common and integrate power supply and two channels of amplification in a single unit. This set up forms the entry point into an NVA pre/power system with the P50 pre-amp and S150 power amp.
P50 PRE-AMP PLUS MONO-BLOCK POWER AMPS
Mono-block power amps are actually two boxes, and come in matched left / right pairs. Each channel is completely independent of the other, and results in less interference between left and right channels, giving better stereo imaging, but the greatest advantage is that each channel has its own power supply, or dual power supplies in the case of the M600. This results in greater dynamics and incite into the music.
MULTI-AMPING
The P50 preamp has three sets of outputs per channel, so we can support bi-amping (and also tri-amping for speakers with this capability).
BI-AMPING
For example, we can add the M300 or M600 mono-block power amps to a system that contains a single stereo power amp. Now our stereo power amp is driving just the tweeters, relieving it of the low frequency current needed to drive bass units. The result is lower distortion, more detail and sweetness. Each mono-block drives only a single bass unit and much less crossover. This results in much less inter-modulation giving better bass and mid-range.
If we already have M300 or M600 mono-block power amps, we can add an S80 stereo power amp or M160 mono-block power amps to drive the tweeters.
TRI-AMPING
Some multi-driver speakers have 3 sets of speaker terminals, allowing you to use separate amps for bass, midrange and treble units. The principles and benefits are the same as bi-amping.
WHEN BI-AMPING IS NOT POSSIBLE
Not all speakers can be multi-amped, some have only a single pair of binding posts. In this case we can not obtain better sound with multi-amping. Instead we must simply use better amplifiers, for example a pair of M600 mono-blocks.
MULTI-AMPING VS SINGLE AMPING
What's better? S150 + M300s or a single pair of M600s? If your speaker has a complex or high-order crossover, or has a uneven impedance curve (especially around the crossover point) then multi-amping is probably the better route to take. In fact, we would always recommend the multi-amp route for speakers with 3rd or 4th order crossovers, as each amplifier then 'sees' less crossover. If your speaker has simple (low-order) crossover networks, and even impedance curves, then we recommend either solution.
TYPICAL UPGRADE PATH
Start with P50 preamp and a stereo power amp - S150 / S300. If your speakers are below average sensitivity (<88db) and / or have a 3rd or 4th order crossover, choose the S150 or, even better, the S300. Buy the best interconnect and speaker cables you can afford.
Add a Balanced Mains Unit to supply your system. UK mains quality can be poor, so there's a very good chance you won't be hearing your system at it's full potential until you try our BMU.
Upgrade your P50 pre-amp to SA specification. We fit a superb 23 step Seiden switch with Audio Note load resistors. More transparency and detail.
Bi-amping - add a set of M300 or M600 mono-block power amps to drive your speakers bass units and use your existing S150 / S300 to drive the tweeters only. Better bass and midrange. More scale and resolution. Sweeter treble.
Upgrade interconnects and speaker cables with our Cable Trade-In Scheme.
NVA Balanced Mains Unit BMU 1KVA
£1,041.67
Stock expected - mid February NEW! Now with Toroidy Audio Grade transformer and soft-start feature. Normal mains is single ended. By changing this to balanced you remove noise and distortion. UK mains quality can be very poor. There's a strong possibility that you… read more
